Contribution of thermal, rheological and physical measurements to the determination of sensorially perceived quality of ice cream containing bulk sweeteners Christos Soukoulis * , Evagellia Rontogianni, Constantina Tzia 1 Laboratory of Food Chemistry and Technology, School of Chemical Engineering, National Technical University of Athens, Polytechnioupoli Zografou, 5 Iroon Polytechniou Str., Athens, Greece article info Article history: Received 18 December 2009 Received in revised form 3 May 2010 Accepted 15 May 2010 Available online 24 May 2010 Keywords: Ice cream Bulk sweeteners Sensory profile Instrumental properties Acceptability abstract The role of rheological measurements, thermal analysis and physical properties such as overrun, instru- mental hardness and melting behavior on sensorial profile mapping of vanilla ice cream was evaluated. Samples with different functional characteristics were prepared partially substituting sucrose by bulk sweeteners. Creaminess apart from thermal properties (glass transition temperature-T g , ice crystal uni- formity-DN mcurve and unfrozen water content-UFW) was poorly related with rheological and physical properties. On the contrary, coarseness, wateriness, greasiness and gumminess perception were found to be well correlated with rheological and thermal properties, overrun, air cells mean size and melting rate. Flavor and taste characteristics were interrelated particularly with melting and thermal character- istics, overrun and air cells mean size. Multivariate exploratory statistical methods revealed that the use of T g , DN mcurve , UFW, instrumental hardness, and melting rate can be used for the effective discrimination of ice creams differing in their sweetener composition suggesting their importance in the design of novel ice cream formulations. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Ice cream is a food with complex colloidal characteristics due to its particular structural elements e.g. partially coalesced fat drop- lets, ice crystals, air cells found dispersed in the aqueous serum phase (Goff, 1997). The structural elements of ice cream contribute significantly to the perception pattern of texture and flavor (Kokini and van Aken, 2006). Texture quantification can be accomplished by the determination of the properties that are related to the col- loidal aspects of ice cream such as microstructure, serum viscoelas- ticity, emulsion characteristics, and thermal properties (Goff, 1997; Goff et al., 1999; Herrera et al., 2007; Regand and Goff, 2003; Chang and Hartel, 2002; Muse and Hartel, 2004). On the other hand, descriptive sensory analysis has been evaluated as a very effective tool for the quantification of the sensorial profile of ice cream as well as for the discrimination of ice cream samples with different compositional characteristics (Guinard et al., 1997; Sou- koulis and Tzia, 2010; Soukoulis et al., 2008). Recently a great number of studies have been carried out in order to investigate the particular relationships of instrumental and phys- icochemical measurements with the sensorial profile of semi-solid dairy desserts such as flavored custards and yogurts (de Wijk et al., 2006a; Frøst and Janhøj, 2007). Creaminess, mouth-coating, tongue, lubrication, friction, coarseness, thickness are sensory attributes of paramount importance for the perceived quality of semi-solids dairy desserts. Dynamic rheological parameters, light scattering and spectroscopic techniques, friction determination, turbidometry have been successfully used for the investigation of the interrelationships of instrumental properties with the sensorial quality of dairy desserts and emulsions (de Wijk et al., 2006b; Janssen et al., 2007). However, although ice cream is among the most common semi-solid dairy desserts, still there is little informa- tion about the role of different instrumental measurements on the perception of flavor and texture attributes. Aim of the present study was the investigation of the role of rheological, thermal and physical properties to the establishment of specific sensory attributes critical for the quantification of sensorial quality of ice cream. 2. Materials and methods 2.1. Bulk sweeteners For the preparation of the ice cream samples sucrose (Hellenic Sugar Industry, Larissa, Greece) has been partially substituted by bulk sweeteners differing in their molecular weight, degree of 0260-8774/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jfoodeng.2010.05.012 * Corresponding author. Present address: Fondazione Edmund Mach, Istituto Agrario di San Michele a/A (IASMA), Centro Ricerca e Innovazione, Area Aliment- azione, via Mach 1, 38010, Italy. Tel.: +39 04616153388. E-mail addresses: chrsoukoulis@yahoo.gr, christos.soukoulis@iasma.it (C. Sou- koulis), tzia@chemeng.ntua.gr (C. Tzia). 1 Tel.: +30 2107723165; fax: +30 2107723163. Journal of Food Engineering 100 (2010) 634–641 Contents lists available at ScienceDirect Journal of Food Engineering journal homepage: www.elsevier.com/locate/jfoodeng